1. Field of the Invention
The present invention relates to a progressive die assembly and a method for manufacturing lamina stacks which include formed features.
2. Description of the Related Art
The manufacture of parts, e.g., stators and rotors for electric motors, ignition assembly cores, or other parts which employ stacked laminas is well known in the art. Typically, the laminas are blanked from a continuous strip of stock material and are then stacked and bound together to form the completed part. Progressive die assemblies for producing lamina stacks, wherein a strip of lamina material is fed through a sequence of punching steps to progressively form the laminas to the desired end configurations, are also well known.
The strips of stock material from which the individual laminas are formed, blanked, and stacked are substantially planar, such that each of the individual laminas formed and blanked from the strip to form the stack is also planar. In this manner, known lamina stacks are limited to a stack of planar laminas in which each individual lamina is disposed entirely within a single plane. In some applications, however, it is envisioned that it will be useful to form lamina stacks including a plurality of stacked, planar laminas with at least one lamina having a portion thereof which is disposed outside of the plane of the remainder of the lamina.
What is needed is a die assembly and method which is an improvement over the foregoing.